G4MonopoleEquation Class Reference

Monopole equation of motion class. More...

#include <G4MonopoleEquation.h>

Inheritance diagram for G4MonopoleEquation:

Public Member Functions
	G4MonopoleEquation (G4MagneticField *mField)
	Constructor.
	~G4MonopoleEquation ()
	Destructor.
virtual void	SetChargeMomentumMass (G4ChargeState particleChargeState, G4double momentum, G4double mass)
	G4EquationOfMotion::SetChargeMomentumMass() implementation.
virtual void	EvaluateRhsGivenB (const G4double y[], const G4double Field[], G4double dydx[]) const
	Given the value of the electromagnetic field, this function calculates the value of the derivative dydx.

Private Attributes
G4double	fMagCharge
	Magnetic charge of the monopole, in e+ units.
G4double	fElCharge
	Electric charge in case of a dyon.
G4double	fMassCof
	Square of the monopole mass.

Detailed Description

Monopole equation of motion class.

Equation of motion define stepper in G4, which defines chord finder, which is required to perform transportation process.

Definition at line 30 of file G4MonopoleEquation.h.

Constructor & Destructor Documentation

G4MonopoleEquation()

G4MonopoleEquation ( G4MagneticField *  mField )

explicit

Constructor.

Parameters

mField

Pointer to the field in which the particle will propagate.

Definition at line 22 of file G4MonopoleEquation.cc.

  : G4EquationOfMotion(mField)
{}

~G4MonopoleEquation()

~G4MonopoleEquation

(

)

Destructor.

Definition at line 26 of file G4MonopoleEquation.cc.

{}

Member Function Documentation

EvaluateRhsGivenB()

void EvaluateRhsGivenB ( const G4double  y[], const G4double  Field[], G4double  dydx[]  ) const

virtual

Given the value of the electromagnetic field, this function calculates the value of the derivative dydx.

Parameters

y	y[6]: 0-2 dr/ds - velocity, 3-5 dp/ds - momentum derivatives.
Field	Field[3]: Field components.
dydx	dydx[8]: Where to store results.

Definition at line 46 of file G4MonopoleEquation.cc.

{
  // Components of y:
  //    0-2 dr/ds,
  //    3-5 dp/ds - momentum derivatives
 
  G4double pSquared = y[3] * y[3] + y[4] * y[4] + y[5] * y[5] ;
 
  G4double Energy   = std::sqrt(pSquared + fMassCof);
 
  G4double pModuleInverse  = 1.0 / std::sqrt(pSquared);
 
  G4double inverse_velocity = Energy * pModuleInverse / c_light;
 
  G4double cofEl     = fElCharge * pModuleInverse ;
  G4double cofMag = fMagCharge * Energy * pModuleInverse;
 
 
  dydx[0] = y[3] * pModuleInverse ;
  dydx[1] = y[4] * pModuleInverse ;
  dydx[2] = y[5] * pModuleInverse ;
 
  // G4double magCharge = twopi * hbar_Planck / (eplus * mu0);
  // magnetic charge in SI units A*m convention
  //  see http://en.wikipedia.org/wiki/Magnetic_monopole
  //   G4cout  << "Magnetic charge:  " << magCharge << G4endl;
  // dp/ds = dp/dt * dt/ds = dp/dt / v = Force / velocity
  // dydx[3] = fMagCharge * Field[0]  * inverse_velocity  * c_light;
  // multiplied by c_light to convert to MeV/mm
  //     dydx[4] = fMagCharge * Field[1]  * inverse_velocity  * c_light;
  //     dydx[5] = fMagCharge * Field[2]  * inverse_velocity  * c_light;
 
  dydx[3] = cofMag * Field[0] + cofEl * (y[4] * Field[2] - y[5] * Field[1]);
  dydx[4] = cofMag * Field[1] + cofEl * (y[5] * Field[0] - y[3] * Field[2]);
  dydx[5] = cofMag * Field[2] + cofEl * (y[3] * Field[1] - y[4] * Field[0]);
 
  //        G4cout << std::setprecision(5)<< "E=" << Energy
  //               << "; p="<< 1/pModuleInverse
  //               << "; mC="<< magCharge
  //               <<"; x=" << y[0]
  //               <<"; y=" << y[1]
  //               <<"; z=" << y[2]
  //               <<"; dydx[3]=" << dydx[3]
  //               <<"; dydx[4]=" << dydx[4]
  //               <<"; dydx[5]=" << dydx[5]
  //               << G4endl;
 
  dydx[6] = 0.;//not used
 
  // Lab Time of flight
  dydx[7] = inverse_velocity;
  return;
}

SetChargeMomentumMass()

void SetChargeMomentumMass ( G4ChargeState  particleChargeState, G4double  momentum, G4double  mass  )

virtual

G4EquationOfMotion::SetChargeMomentumMass() implementation.

Reads particle properties for equation of motion definition.

Parameters

particleChargeState	Charge information about the particle. Luckily, G4ChargeState have magnetic charge member variable. Magnetic charge is taken from it in e+ untis.
momentum	This argument of base function is ignored.
mass	Mass of the particle.

Definition at line 30 of file G4MonopoleEquation.cc.

{
  G4double particleMagneticCharge = particleChargeState.MagneticCharge();
  G4double particleElectricCharge = particleChargeState.GetCharge();
 
  //   fElCharge = particleElectricCharge;
  fElCharge = eplus * particleElectricCharge * c_light;
 
  fMagCharge =  eplus * particleMagneticCharge * c_light ;
 
  fMassCof = particleMass * particleMass ;
}

Member Data Documentation

fElCharge

G4double fElCharge

private

Electric charge in case of a dyon.

Definition at line 74 of file G4MonopoleEquation.h.

fMagCharge

G4double fMagCharge

private

Magnetic charge of the monopole, in e+ units.

Definition at line 73 of file G4MonopoleEquation.h.

fMassCof

G4double fMassCof

private

Square of the monopole mass.

Definition at line 75 of file G4MonopoleEquation.h.

---

The documentation for this class was generated from the following files:

• simulation/monopoles/include/G4MonopoleEquation.h
• simulation/monopoles/src/G4MonopoleEquation.cc